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排序方式: 共有187条查询结果,搜索用时 15 毫秒
101.
Hadi Mahmoudi Moghaddam Hadi Beitollahi Somayeh Tajik Shohreh Jahani Hojatollah Khabazzadeh Reza Alizadeh 《Russian Journal of Electrochemistry》2017,53(5):452-460
A novel carbon paste electrode modified with ZnO nanorods and 2-(4-oxo-3-phenyl-3,4-dihydroquinazolinyl)-N′-phenyl-hydrazinecarbothioamide (2PHCZNCPE) was fabricated and employed to study the electrocatalytic oxidation of droxidopa, using cyclic voltammetry, chronoamperometry and square wave voltammetry as diagnostic techniques. It has been found that the oxidation of droxidopa at the surface of modified electrode occurs at a potential of about 435 mV less positive than that of an unmodified carbon paste electrode. Square wave voltammetry exhibits a linear dynamic range from 7.0 × 10–8 to 3.0×10?4 M and a detection limit of 45.0 nM for droxidopa. Finally this modified electrode was used for simultaneous determination of droxidopa and carbidopa. 相似文献
102.
M. Mahmoudi 《Algebra Universalis》1999,41(3):155-175
This paper deals with the internal notion of injectivity for Boolean algebras in the topos of M-sets. Given that, for ordinary Boolean algebraas, injectivity is the same as completeness (Sikorski's theorem) and the injective hull is the same as normal completion, we investigate here how the internal notion of completeness relates to internal injectivity. Further, we consider the internal injectivity of the initial Boolean algebra 2 which is equivalent to the prime ideal theorem for Boolean algebras in this topos. Before we turn specificially to Boolean algebras, we develop the bassic general facts concerning internal injectivity in MSet for arbitrary equational classes of algebras. 相似文献
103.
Azadeh Mansouri Ahmad Mahmoudi Aznaveh Farah Torkamani-Azar J. Afshar Jahanshahi 《Optical Review》2009,16(2):49-53
In objective image quality metrics, one of the most important factors is the correlation of their results with the perceived
quality measurements. In this paper, a new method is presented based on comparing between the structural properties of the
two compared images. Based on the mathematical concept of the singular value decomposition (SVD) theorem, each matrix can
be factorized to the products of three matrices, one of them related to the luminance value while the two others show the
structural content information of the image. A new method to quantify the quality of images is proposed based on the projected
coefficients and the left singular vector matrix of the disturbed image based on the right singular vector matrix of the original
image. To evaluate this performance, many tests have been done using a widespread subjective study involving 779 images of
the Live Image Quality Assessment Database, Release 2005. The objective results show a high rate of correlation with subjective
quality measurements. 相似文献
104.
Computational Management Science - The inclusion of emojis when solving natural language processing problems (e.g., text‐based emotion detection, sentiment classification, topic analysis)... 相似文献
105.
Pozveh Azam Abedini Kowsari Elaheh Hashemi Mohammad Mahmoudi Mirjafari Zohreh 《Research on Chemical Intermediates》2020,46(2):1329-1351
Research on Chemical Intermediates - This paper presents the preparation of a new epoxy nanocomposite of functionalized graphene oxide (FGO) and iron pentacarbonyl [Fe(CO)5] (IPC) as... 相似文献
106.
Novel magnetic hybrid nanomaterials 1 (LaFeO3.Fe3O4@SiO2-NH2/PW12) were synthesized by supporting phosphotungstic acid (H3PW12O40; PW12) on LaFeO3.Fe3O4 nanomaterials through sono-assisted method. The synthesized nanomaterials were fully characterized by using FT-IR, XRD, UV–vis, BET-BJH, VSM, SEM, and TEM analyses. FT-IR, XRD, and UV–vis confirmed successful synthesis of nanomaterials. The SEM and TEM images revealed spherical morphology with core-shell structure for hybrid nanomaterials 1 . VSM results confirmed the magnetic property of hybrid nanomaterials 1 and suggested it as easily recyclable photocatalyst for removal of organic dyes from aqueous solution. The photocatalytic activity of hybrid nanomaterials 1 has been studied over the degradation of methylene blue (MB) and methyl orange (MO) solution under UV–vis light irradiation. Importantly the hybrid nanomaterials 1 showed outstanding degradation efficiency for MB solution in comparison with bare LaFeO3.Fe3O4 and PW12. The photocatalytic activity was enhanced mainly due to the high efficiency in separation of electron–hole pairs induced by the remarkable synergistic effects of LaFeO3.Fe3O4 and PW12 semiconductors. After the photocatalytic reaction, the nanocomposite can be easily separated from the reaction solution and reused several times without loss of its photocatalytic activity. Trapping experiments indicated that hole (hVB+) and •OH radicals were the main reactive species for dye degradation in the present photocatalytic system. On the basis of the experimental results and estimated band gaps, the mechanism for the enhanced photocatalytic activity was proposed. 相似文献
107.
Dinara S. Shapenova Alexey A. Shiryaev Michael Bolte Mercedes Kukułka Dariusz W. Szczepanik James Hooper Maria G. Babashkina Ghodrat Mahmoudi Mariusz P. Mitoraj Damir A. Safin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):12987-12995
Extensive experimental and theoretical investigations are reported on the nature of resonance-assisted hydrogen bonding phenomenon (RAHB) and its influence on photophysical properties of the newly designed dyes differing in donor–acceptor properties, namely ethyl N-salicylideneglycinate ( 1 ), ethyl N-(5-methoxysalicylidene)glycinate ( 2 ), ethyl N-(5-bromosalicylidene)glycinate ( 3 ) and ethyl N-(5-nitrosalicylidene)glycinate ( 4 ). All compounds are thermochromic in the solid state and they contain a typical intramolecular O−H⋅⋅⋅N hydrogen bond formed between the hydroxyl hydrogen atom and the imine nitrogen atom, yielding the enol form in the solid state. It is unveiled, that the magnitude of RAHB effect fine tunes the strength of the O−H⋅⋅⋅N bonding and accordingly the relative populations of the enol, cis-keto and trans-keto forms leading to variation of the photophysical properties of 1 – 4 . It is determined, that the electron-withdrawing NO2 in 4 amplifies the most RAHB effect causing the breaking of the O−H⋅⋅⋅N hydrogen bond and accordingly formation of the dominant cis-keto isomer in both the solid state and EtOH. To this end, the UV/Vis spectra of 1 – 3 in EtOH revealed the exclusive presence of the enol form, while the prevalent contribution of the cis-keto form was found for 4 . Furthermore, only compound 4 is emissive in the solid state in ambient condition due to dual emission arising from the cis-keto* and trans-keto* forms, while 2 was found to be highly emissive in EtOH. It is revealed qualitatively and quantitatively, based on the ETS-NOCV charge and energy decomposition scheme and the EDDB population-based method, that RAHB is strongly a non-local phenomenon based on electrons pumping or sucking through both the π- and σ-channels, which accordingly exerts chemical bonding changes at both the phenyl ring and predominantly a distant O−H⋅⋅⋅N area. 相似文献
108.
Experimental Techniques - The Virtual Point Transformation (VPT) makes it possible to experimentally identify the full DoF FRF matrix by projecting the measured displacements onto the Interface... 相似文献
109.
M. Sahrai A. Maleki R. Hemmati M. Mahmoudi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,56(1):105-112
We investigate the dynamical behavior of the dispersion and the absorption
in a V-type three level atomic system. It is shown that in the presence of
decay-induced interference the probe dispersion and absorption are phase
dependent. We find that an incoherent pumping field provides an additional
control parameter for switching the group velocity of a light pulse. The
required switching times for switching the group velocity of a probe field
from subluminal to superluminal pulse propagation is then discussed. 相似文献
110.